John t



JOHN T. DENNISTON, OF LYONS, NEW YORK.

CONDENSER FOR STEAM-ENGINES.

Specification of Letters Patent No.

To all who/m it may concern.'

Be it known that I, Jol-IN T. DENNISTON, of Lyons, in the county of Wayne and State of New York, have invented a new and useful Improvement in Vacuum Apparatus" for LownPressure Steam-Engines; and I do hereby declare that the followingis a full,

clear, and exact description of the same, reference .being had to the accompanying drawing, forming part of this speciiication, in which- Figures l and 2, are vertical sections at right angles to each other of my `improved vacuum apparatus; the plane of section of Fig. l beingindicated by a line w, m, in Fig. 2 and that Aof Fig. 2, by aline y, y, in Fig. l. Fig. 3, Ais a plan` of the interior a of one oi" the condensers.

Similar letters of reference indicate corresponding parts 1n the several figures.

The object of this invention is, first to` form a more perfect vacuum; second, to complete the condensation and obtain the vacuum at an earlier point in the stroke of the engine. y i s To enable others skilled in the art to make and use `my invention, I will proceed to describe its construction and operation.

The example of my invention given in the accompanying diagram is adapted `for river boat engines, in which the vacuum apparatus is above the water line, or 'for stationary engines whose condensing apparatus is at a higher elevation than the source from whence the water for condensation is derived. y

In carrying out the invention, two separate condensers, each having a completel and distinct set of pumps and all necessary appendages are employed, one of the condensers being used for the purpose of producing the vacuum on one side of the piston and the other for producing the vacuum on the opposite side thereof.`

A, is a metal boX having a horizontal partition a, a, extending all across and from end to end, and having the part below this partitionc, a, divided into two separate chambers b and c, by an upright partition d, and the part above the partition a, a,

divided by anupright partition e, into two chambers y, g, the former of which constitutes the lower part of and supports the main part C, of one of the two condensers and the other, g, has the cylinder of a pump hot water.

15,604,`dated August 26, 1856.

B, erected upon it. A', is a box in all respects like A, arranged side by side with but at some distance from A, and having a similar arrangement of partitions and chambers and having arranged on the top of it, the other condenser C', and a pump B, similar to B. From the bottom of each chamber b, a pipe h, leads to the river or source from whence the water to effectcondensation is obtained, for the purpose of supplying cold water to the condenser and at `the bottom of each chamber c, is a waste pipe z', for the purpose of carrying ofi' the Between each chamber f and the chamber below it, there is a communication iitted with va puppet valve j, which opens upward; and between each chamber g, and the chamber c, below it, there is a puppet valve 7c, which opens downward. The valves y', and k, belonging `to each condenser are connected with opposite ends of a small beam Z, which works on a pin m, in such a manner that both valves open and close together. Between each chamber f, and its corresponding chamber g, there is a ,communication fitted with two valves, viz:

a sluice valve a, which is adjustable by a screw and nut 0 tovary the width of opening and a flap valve toward the chamber g. s i s D, D', are the pistons of the pumps B, B, each of which is hollow and carries at the top, a small pump E or E,`tted with an inlet valve Q, communicating through the piston D,or D of the larger pump with the interior of thelarger pump, and a dis-` charge valve @communicating with the atmosphere.V The larger pumps B, B, are for pumping out the water` from the condensers and the smaller ones are air pumps for pumping out the air. The heads or top parts of the pistons D, D', of the larger pumps, are made of conical` or dome shape to constitute air chambers s, s, for the collection under the air pumps of the air which rises Vto the surface of the water in the larger pumps. The pistonsD, D", are connected by rods P, P, with opposite ends `of a beam F,which is supported and rocks -the larger pumps.

ing in contact with bridges I, I', which are secured across the tops of the cylinders of The whole of the air pump E or E', moves with the piston of its respective water pump B or B', until near the end of the stroke of the latter, up or down, one of the stops t, u, strikes the bridge and holds its piston H or H', stat-ionary while its cylinder moves on till the end of the stroke of the water pump.

The upper parts of the condensers are fitted with cells or perforated cups o, o, of such construction and with such an arrangement of spaces w, fw, between them, see Figs. 1 and 3, that they will lill readily with water when water rises into the condenser, but when the water leaves the lower part of the condenser, will retain a large quantity of water which drops through their perforated bottoms and falls in showers through the condenser. The eduction pipes from the engine cylinder, of which one is shown, K, Fig. 1, enter the condensers above the perforated cups or cells and each is furnished with a `valve Q, opening into the condenser. On the top of each condenser is a small air pump L, or L', having an inlet valve x, communicating with the interior of the condenser and anvoutlet valve @communicating with the atmosphere. The piston M of each of these pumps has its rod attached to one end of one of two levers N, N', which works on a fulcrum in a fixed stand O, and has its other end connected with thel beam F, in such a manner that the piston of the air pump L or L' will be rising while the piston of its respect-ive pump B or B', is descending and yvice versa.

The operation of the apparatus will now be described. The condensers, each in turn, are completely filled with water by atmospheric pressure acting on the surface of the river or other source from which the water for condensation is derived, the filling of either condenser taking place through the pipe h, chamber b and valve y', see Fig. 2, at a time when that end of the cylinder with which it connects is taking steam; the piston A of its pump B or B', being at that time descending and by-its pressure on the water in the pump keeping the valve p, closed and the valves le, y', open. The action of the pump B or B', is reversed, z'. e. its down "stroke commences, just before the eduction of steam to its respective condenser takes place, and the elfect of this action of the pump, is to close the valves 7' and 7c, and open the valve 79, thereby causing the water to flow from the vcondenser into the pump, and in consequence of the stroke of the pump changing before the educt-ion of steam, suiiicient water will have left the condenser when eduction commences, to make room for the incoming steam, which opens the valve Q, and rushes in between the water cups fo, o, and among the descending shower of water, and is all condensed by the time the engine piston has made a very small portion of its stroke. The water continues to pass from the condenser to the pump (suppose the pump B) till the stroke of the pump is reversed, the air which has been set free from the steam' rising all the time to the top of the water and into the chamber s, where it is collected ready to be taken out by the air pump E, as will be presently described. Then the stroke of the pumps B, B', is reversed previously to the eduction of the steam from the other end of the steam cylinder, and the pump B,-whichlis the one supposed to have been particularly referred to in the previous description of the operationwcommences its descent, the valve p, closes and the valves j, la, open, and consequently the descending piston forces out the water from the pump B, through the valve 7c, the chamber c, and waste pipe z', while the condenser C, which at the time of the reversal of the stroke of the pump contained a vacuum, is filled again with water forced by the pressure of the atmosphere up the pipe 7L, in readiness to condense the steam that will be admit-ted when the engine passes its center. While one condenser is receiving steam and in operation, the other condenser is filling ready for the change of stroke of the engine piston. The air pumps on the top of the water pump pistons are operated to extract the air from the chambers s, s, in the downward stroke of the water pumps, by the stop u, coming in contact with the bridges I, I', and the air thus extracted remains in their cylinders till near the termination of the vsucceeding upward stroke when itis expelled from under the pistons by the arrest of the latter by the stops t, coming in contact with the bridges I, I'. The air liberated from the steam and rising to the top of the condensers enters the pumps L, L', just as the water rises to the top of the condensers and is expelled through the valve c, of either condenser during the condensationv of the steam when the respective pump piston D or D', is extracting the water from the condenser. Then the condenser is placed entirely below the water line, the pumps L, L', may bedispensed with by the employment of a valve opening upward from the condenser byv pressure from the inside, the air beingk expelled by gravitation.

The advantages of this vacuum apparatus consist, first, in having all the water necessary for condensing the steam from one stroke of the engine piston, in the condenser before the steam is admitted, by which means the more rapid condensat-ion of the steam'is effected; second, in dispensing with the cumbrousl air pumps commonly employed, and saving much of the power re` capacity to extract the water of conden" sation and the quantity of water which has been necessary to effect the condensation, the latter quantity being regulated by the sluice valve n, as the quantity entering the condenser will be equal to what is drawn out by the pump. The aggregate capacity of the four air pumps E, E', and I, I', requires to be just sufficient to contain the quantity of air set free during one revolution of the engine and as the air when expelled is subjected to a pressure not very materially less than that of the atmosphere, the pumps need be but very small. But the most important advantage that is expected to be derived from this improvement is the formation of nearly a perfect vacuum, and thereby dissipate the resisting force which amounts to from two to four pounds to the square inch in the existing mode.

What I claim as my invention and desire to secure by Letters Patent, is-

l. Forming a partial vacuum before `the commencement of the eduction of the steam from the engine to the condenser, by first fitting t-he condenser with water and then partially withdrawing the water to form steam space substantially as herein set forth.

2. Suspending the water in the condenser in a niunber of cups or cells o, v, with perforated bottoms and passages fw, w, between them, thus causing the steam to circulate among and over and under the water in the cups and through the shower of water falling through the condenser.

JOHN T. DENNISTON.

Witnesses:

HUGH` JAMESON, LYMAN LYON. 

